Leak Down Test

1. Immerse the lash adjuster in clean diesel fuel.

CAUTION:
1. The lash adjuster is a precision part. Keep it free from dust and other foreign matter.
2. Do not disassemble lash adjuster.
3. When cleaning lash adjuster, use clean diesel fuel only.

NOTE: Diesel fuel temperature should be 15 - 20° C (59 - 68° F).

2. While lightly pushing down inner steel ball using tool No. MD998442, or equivalent, move the plunger up and down for or five times to bleed air. Use of the retainer helps the air bleeding of the rocker arm mounted type lash adjuster.
3. Remove the tool and press the plunger. If the plunger is hard to be pushed in, the lash adjuster is normal. If the plunger can be pushed in all the way readily, bleed the lash adjuster again and test again. If the plunger is still loose, replace the lash adjuster.

CAUTION: Immediately after air bleeding, hold lash adjuster upright to prevent fuel from spilling.





4. After air bleeding, set the lash adjuster on the leak down tester tool No. MD998440, or equivalent.





5. After plunger has gone down 0.2 - 0.5 mm (0.008 - 0.020 inch), measure time taken for it to go down 1 mm (0.039 inch). Replace if measured time is not within 4 - 20 seconds/1 mm (0.04 inch).